In this paper

the errors of planar near field scanning technique are analyzed for ultra-low-side-lobe antennas

and the concept of the total planar near-field amplitude and phase measured error is proposed.The relationship between the total errors and the far field pattern is then presented for the ultra-low-side-lobe antennas under test in planar near field measurement

and the related computer simulations are carried out.Finally

a "self-correction" method for reducing the multiple-reflection errors and the measurement environment errors is presented

which can improve efficiently the measurement precision in planar near-field measurement.